Diastereoselective α-amidoalkylation of N,O-acetal,derivated from controlled regio and diastereoselective reductionof (S)-N-(4-methoxybenzyl)-3-silyloxyglutarimideprovided two diastereomeric 6-allyl-5-silyloxy-2-piperidinonesin 76:24 selectivity. The transformation of the major diastereomerinto a known advanced intermediate allowed the synthesis of (+)-febrifugineand (+)-isofebrifugine.
通过对(S)-N-(4-甲氧基苄基)-3-
硅氧基戊二
酰亚胺进行受控的区域和非对映选择性还原,进而得到N,O-
缩醛衍
生物的非对映选择性α-
氨基烷基化反应,在76:24的选择性下提供了两种非对映异构的6-烯丙基-5-
硅氧基-2-
哌啶酮。将主要的非对映异构体转化为已知的高级中间体,实现了(+)-
乙胺嘧啶和(+)-异
乙胺嘧啶的合成。